Cnidaria is a phylum within Kingdom Animalia which consists of hydras, jellies (or jellyfish), sea anemones, and corals. All cnidarians are radially symmetrical, and there are two main radially symmetrical body types.
The stock market crash, on black Tuesday (October 29, 1929) began the Great Depression.
The Great Depression originated in the United States; historians most often use as a starting date the stock market crash on October 29, 1929, known as Black Tuesday. The depression had devastating effects in virtually every country, rich or poor.